1. Field of the Invention
The invention disclosed herein relates to an aileron accessory in the tailgate of light trucks.
2. Description of the Related Art
Pick-up trucks are a popular form of vehicle used by both individuals and small businesses alike. They provide a means for hauling light cargo and bulky articles that could not otherwise be carried in a typical sedan, coupe or other personal vehicle, as well as for other personal transportation needs, such as for commuting to work or for running errands. When the pick-up truck is not used for hauling light cargo, the open truck bed usually remains empty and open.
The open truck bed in a pick-up truck causes aerodynamic drag on the vehicle, reducing its efficiency and gas mileage. The principle source of aerodynamic drag in the bed of a pick-up truck is the tailgate. This abrupt vertical end of the vehicle prevents a smooth, gradual convergence of the aerodynamic streamlines from around the sides and bottom of the vehicle, causing separation of the streamlines from the vehicle and a zone of low pressure eddies directly behind the tailgate. This zone of low pressure acting on the exterior of the tailgate holds back the vehicle, causing increased aerodynamic drag on the vehicle.
Various techniques have been used to reduce the drag caused by the tailgate. One has been to simply place the tailgate in the lowered position. However, this is unlawful in many jurisdictions, as well as causing a potential hazard of releasing any cargo in the bed.
Another common solution has been to remove the tailgate and replace it with an open mesh, flexible net-like apparatus. This allows a significant amount of air flow and a consequent reduction in drag, as well as retaining any cargo in the bed. However, this tailgate net is unsuitable for carrying friable or granular materials, such as sand or gravel, which may flow through the mesh openings.
U.S. Pat. No. 1,259,088, issued to Enright on Mar. 12, 1918, discloses an end gate for a mobile cargo container, such as a wagon bed, which is operable with a handle connected to an eccentric crankshaft. This general concept may be applicable to the solution for relieving aerodynamic drag on a tailgate. However, the operating mechanism is bulky and cumbersome, and could not, as described, maintain the attitude or position of the end gate at highway speeds common today.
U.S. Pat. No. 3,977,718, issued to Nordberg on Aug. 31, 1976, discloses a turnable truck gate. It is comprised of a tailgate divided horizontally into two sections, wherein each section pivots to an open position. This design relieves the aerodynamic drag, but defeats its utility as a tailgate because the upper section is permanently engaged to the sides of the truck bed, and cannot be disengaged and lowered as with a conventional tailgate. Any heavy item of cargo must be lifted above the top section of the tailgate.
U.S. Pat. No. 4,200,328, issued to Morgan on Apr. 29, 1980, discloses a tailgate construction. One embodiment of that invention included a tailgate comprised of a frame with several horizontal louver panels. Each panel is pivotally hinged at its upper edge, allowing the body of each panel to swing outward. Each panel is held in the open position by a hook latch. While this design relieves the aerodynamic drag on a truck tailgate, it is difficult and cumbersome to operate, and each panel can be opened only to one position, as determined by the size and placement of the hook latch.
U.S. Pat. No. 4,475,759, issued to Wine on Oct. 9, 1984, discloses a pick-up truck having a streamlining tailgate. The streamlining tailgate is comprised of a section which pivots about a horizontal transverse axis within the side frame of the tailgate at either a midpoint or at the top edge of the section. The section is held in various attitudes by engagement with indices in an external arcuate bracket. Since the brackets are external to the tailgate, they pose a possible obstruction to cargo and undesirable visual element within the truck bed.
U.S. Pat. No. 5,468,037, issued to Peterson et al. on Nov. 21, 1995, discloses a dual pivot pick-up tailgate. The tailgate is comprised of a panel disposed within a frame around the sides and bottom of the panel. The panel engages the frame at its upper corners and pivots about a horizontal transverse axis through these points of engagement. The pivotal engagement points are capable of longitudinal translation along the respective top edges of the truck bed sides. This allows the tailgate section to pivot horizontally and slide forward, thereby providing an opening in the tailgate for relieving aerodynamic drag. The disadvantage of this design is that the sliding panel section, when in the opened position, substantially reduces the volumetric cargo capacity of the truck bed.